Taxpayers in Norfolk and Suffolk saw a significant rise in earnings over five years, according to newly-released figures from HMRC.

The data shows that the average taxpayer in Norfolk made £28,500 over the 12 months in 2015-16, with some taxed on a combination of income from regular jobs, self-employment and pensions. It represents an increase of 21% on 2010-11.

Despite the rise, the average total income for taxpayers in the area remains 15% lower than the UK average of £33,400.

The increase may be partially explained by an increase in the tax-free personal allowance, as the HMRC data only includes those who pay income tax.

Despite the allowance increasing from £6,475 in 2010-11 to £10,600 five years later, an estimated 1,000 more workers were taxed in Norfolk in 2015-16.

Taxpayers in Norfolk paid an average £4,130 in income tax over 2015-16. With 426,000 people taxed in the area, it amounted to a total contribution of £1.76bn to government coffers.

The average income of taxpayers in Norfolk was lower than across the East of England, where the mean was £35,000.

In Suffolk the average taxpayer earned £31,600 over the 12 month period, a 21% rise on 2010/11, but 5% below the national average. They paid an average of £5,110 in income tax over 2015-16, which amounted to £1.81bn from 355,000 people.

In addition, 49,000 people in Norfolk and 43,000 in Suffolk paid tax on money earned through self-employment, including those who work for themselves full-time or who run a business alongside a main job.

District-by-district breakdown (East Anglia):

• £36,800 – Suffolk Coastal

• £34,800 – Babergh

• £34,100 – Braintree

• £33,800 – St Edmundsbury

• £33,700 – Mid Suffolk

• £32,300 – Colchester

• £30,800 – South Norfolk

• £30,100 – Broadland

• £29,000 – North Norfolk

• £28,000 – King’s Lynn & West Norfolk

• £27,700 – Breckland

• £27,400 – Tendring

• £27,200 – Forest Heath

• £26,900 – Norwich

• £26,800 – Ipswich

• £25,400 – Fenland

• £25,600 – Great Yarmouth

• £25,700 – Waveney

The London borough of Kensington and Chelsea had the UK’s highest average income, with 74,000 taxpayers making an average of £178,000. In contrast, the lowest average income was in Blackpool, at £22,300.